package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.RequiredArgsConstructor;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@RequiredArgsConstructor
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    private final StringRedisTemplate stringRedisTemplate;
    private final ISeckillVoucherService seckillVoucherService;
    private final RedisIdWorker redisIdWorker;
    private final RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    private static final ExecutorService SECKILL_ORDER_EXCUTOR=Executors.newSingleThreadExecutor();

    private IVoucherOrderService proxy;
    static{
        SECKILL_SCRIPT=new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    @PostConstruct
    private void Init(){
        SECKILL_ORDER_EXCUTOR.submit(new VoucherOrderHandler());
    }
//    private BlockingQueue<VoucherOrder>orderTasks=new ArrayBlockingQueue<>(1024*1024);
//    private class VoucherOrderHandler implements Runnable{
//        @Override
//        public void run() {
//            while(true){
//                try {
//                    //获取队列中的信息
//                    VoucherOrder voucherOrder = orderTasks.take();
//                    //创建订单
//                    handleVoucherOrder(voucherOrder);
//                } catch (Exception e) {
//                    log.error("处理订单异常",e);
//                }
//
//            }
//        }
//    }
String  queueName="stream.orders";
        private class VoucherOrderHandler implements Runnable{
        @Override
        public void run() {
            while(true){
                try {
                    //获取消息队列中的信息    XREAD GROUP g1 c1 count 1 block 2000 Streams.order>
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    //判断消息获取是否成功
                    if(list==null||list.isEmpty()){
                        //失败没有消息继续下一次循环
                        continue;
                    }
                    //解析消息中的订单消息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //有消息则下单
                    handleVoucherOrder(voucherOrder);
                    //ACK确认 SACK stream.orders g1 id
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    handlePendingList();
                }

            }
        }
    }

    private void handlePendingList() {
        while(true){
            try {
                //获取pending-list中的订单信息    XREAD GROUP g1 c1 count 1 block 2000 Streams.order 0
                List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                        Consumer.from("g1", "c1"),
                        StreamReadOptions.empty().count(1),
                        StreamOffset.create(queueName, ReadOffset.from("0"))
                );
                //判断消息获取是否成功
                if(list==null||list.isEmpty()){
                    //失败没有异常消息跳出循环
                    break;
                }
                //解析消息中的订单消息
                MapRecord<String, Object, Object> record = list.get(0);
                Map<Object, Object> values = record.getValue();
                VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                //有消息则下单
                handleVoucherOrder(voucherOrder);
                //ACK确认 SACK stream.orders g1 id
                stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
            } catch (Exception e) {
                log.error("处理pending-list异常",e);
                try {
                    Thread.sleep(50);
                } catch (InterruptedException ex) {
                    throw new RuntimeException(ex);
                }
            }

        }
    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //获取用户
        Long userId = voucherOrder.getUserId();
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //获取锁
        boolean isLock = lock.tryLock();
        if (!isLock) {
            //获取锁失败,返回错误或重试
            log.error("不允许重复下单!");
            return;
        }
        try{
            //获取代理对象(事务)

             proxy.createVoucherOrder(voucherOrder);
        }finally {
            lock.unlock();
        }

    }

    @Override
    public Result seckillVoucher(Long voucherId)  {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        long orderId = redisIdWorker.nextId("order");
        //1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString(),String.valueOf(orderId)

        );
        int r = result.intValue();
        //2.判断结果为0
        if (r!=0){
            //2.1不为0，代表没有资格购买
            return Result.fail(r==1?"库存不足":"不能重复下单");
        }
        //获取代理对象
        proxy =(IVoucherOrderService) AopContext.currentProxy();

        //3.返回订单id
        return Result.ok(0);
    }
//    @Override
//    public Result seckillVoucher(Long voucherId)  {
//      //获取用户
//        Long userId = UserHolder.getUser().getId();
//
//        //1.执行lua脚本
//        Long result = stringRedisTemplate.execute(
//                SECKILL_SCRIPT,
//                Collections.emptyList(),
//                voucherId.toString(), userId.toString()
//
//        );
//        int r = result.intValue();
//        //2.判断结果为0
//        if (r!=0){
//            //2.1不为0，代表没有资格购买
//            return Result.fail(r==1?"库存不足":"不能重复下单");
//        }
//      //2.2为0，有购买资格，存储到阻塞队列
//        VoucherOrder voucherOrder = new VoucherOrder();
//        long orderId = redisIdWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        voucherOrder.setUserId(UserHolder.getUser().getId());
//        voucherOrder.setVoucherId(voucherId);
//        //创建到阻塞队列
//        orderTasks.add(voucherOrder);
//        //获取代理对象
//       proxy =(IVoucherOrderService) AopContext.currentProxy();
//
//        //3.返回订单id
//      return Result.ok(0);
//    }
//    @Override
//    public Result seckillVoucher(Long voucherId)  {
//        //查询优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        //判断秒杀是否开始
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            //尚未开始
//            return Result.fail("秒杀尚未开始");
//        }
//        //判断秒杀是否结束
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            //尚未开始
//            return Result.fail("秒杀已经结束");
//        }
//        //判断库存是否充足
//        if (voucher.getStock()<1) {
//            return Result.fail("库存不足!");
//        }
//        Long userId=UserHolder.getUser().getId();
//       //尝试创建锁对象
////        SimpleRedisLock simpleRedisLock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        //获取锁
//        boolean isLock = lock.tryLock();
//        if (!isLock) {
//            //获取锁失败,返回错误或重试
//            return Result.fail("不允许重复下单!");
//        }
//        try{
//            //获取代理对象(事务)
//            IVoucherOrderService proxy =(IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        }finally {
//            lock.unlock();
//        }
//    }
    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        Long userId=voucherOrder.getUserId();
            //查询订单
            int count = query().eq("user_id", userId).
                    eq("voucher_id", voucherOrder.getVoucherId()).
                    count();
            if (count>0) {
                //用户已经购买过，不允许再买
                log.error("用户已经购买过一次!");
                return;
            }
            //扣减库存
            boolean success=seckillVoucherService.update()
                    .setSql("stock=stock-1")
                    .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock",0)//where id = ? and stock = ?
                    .update();
            if (!success){
                log.error("库存不足！");
                return;
            }
            //创建订单
           save(voucherOrder);

    }
}
